This invention is in the field of development of new polymorphs of 5-amino or substituted amino 1,2,3-triazole (CAI) as well as substituted derivatives thereof, of orotates of 5-amino or substituted amino 1,2,3-triazoles as well as substituted derivatives thereof, and of formulations of 5-amino or substituted amino 1,2,3-triazoles as well as substitutes derivatives thereof and orotic acid (in optimum ratios of base:acid). The objective is to develop new polymorphs of 5-amino or substituted amino 1,2,3-triazoles as well as substitutes derivatives thereof, to improve chemical, biological, pharmacokinetic and toxicokinetic properties and improve therapeutic properties, including, but not limited to anticancer activity, antimetastatic activity, calcium-mediated signal transduction, antiangiogenic, anti-PI3, anti-COX2, apoptosis, down regulation of BCR-ABL protein in chronic myeloid leukemia, regulation of HIV LTR transcription or anti-VEGF1 properties.
In 1986, 5-amino or substituted amino 1,2,3-triazole compounds as well as substituted derivatives thereof were shown to have anticoccidial activity. U.S. Pat. No. 4,590,201, issued to R. J. Bochis et el., 1986, describes the method of preparing 5-amino-1-(4-[4-chlorobenzoyl]-3,5-dichlorobenzyl)-1,2,3-triazole-4 carboxamide (L651582 or CAI) which included use of sodium azide to synthesize one essential intermediate in the pathway, 3,5-dichloro-4-(4-chlorobenzoyl)benzyl azide. Subsequently, L651582 or CAI was shown to inhibit selected signal transduction pathways including those which involve calcium influx, the release of arachidonic acid and the generation of inositol phosphates. U.S. Pat. No. 5,359,078, issued to E. C. Kohn et al, 1994. “L651582” as used herein represents L6515182, CAI, Carboxyamidotriazole, NSC 609974 or 99519-84-3 described in prior art.
U.S. Pat. No. 5,912,346 issued to F. Wehrmann, 1999 then described inorganic and organic salts of L651582, and in particular described the process of preparing the orotate salt of L651582. The L651582 was prepared by the process described in U.S. Pat. No. 4,590,201. The L651582: Orotate was in the ratio of 2:1 (base:acid) as characterized by proton NMR and had a Melting Point of 234-235° C. As described above, the synthesis of the intermediate 3-(4-chlorobenzoyl)-4-chlorobenzyl azide was carried out using the intermediate 3-(4-chlorobenzoyl)-4-chlorobenzoyl bromide and sodium azide in ethanol. U.S. Pat. No. 5,912,346 described improved antitumor activity of L651582 Orotate (CAI Orotate, base:acid, 2:1) compared with that of equivalent dose of L651582 in the androgen-independent Dunning R-3227-AT-1 prostate cancer model in rats.
Carboxyamidotriazole, L651582, CAI, NSC 609974, or 99519-84-3, an inhibitor of calcium-mediated signal transduction, is one of the first cytostatic signal inhibitory anti-cancer drugs discovered. It was tested in patients suffering from solid cancers in Phase I, Phase II and Phase III trials at the National Cancer Institute. However, the NCI stopped the development of L651582 because it failed to demonstrate efficacy in human trials and/or was plagued by poor bioavailability, severe gastrointestinal toxicity, neurotoxicity and problems of tolerability that prevented optimum dosing to achieve therapeutic effect. Capsules of micronized formulation of L651582 in PEG-400 were used in the clinical studies to improve bioavailability of the drug. Kohn E C et al., Clinical Cancer Res 7:1600-1609 (2001); Bauer K S et al., Clinical Cancer Res 5: 2324-2329 (1999); Berlin J et al., J Clin One 15: 781-789 (1997); Berlin J et al., Clinical Cancer res 8: 86-94 (2002); Yasui H et al., J Biol Chem 45:28762-28770 (1997); Alessandro R et al., J Cell Physiol 215: 111-121 (2008).
Therefore, L651582 orotate (base:acid 2:1) described in U.S. Pat. No. 5,912,346, represented a potential way to salvage this promising drug, L651582, by improving its efficacy, based on preclinical studies. However, problems were encountered in the scaling up of the process of preparing L651582 orotate (2:1 ratio) in bulk quantities, according to the method described in U.S. Pat. No. 5,912,346.

With regard to the use of orotic acid in intensifying the analgesic effects of drugs, U.S. Pat. No. 4,061,741, issued to Wawretschek W et al, 1977, describes use of dextropropoxyphene-HCl, laevopropoxyphene-HCl, or sodium salicylate in combination with choline orotate, and concludes that a drug formulation in combination with choline orotate gave the best effects. Clearly, prior art presents contradictory teachings about the proportions and chemical nature of orotic acid bonding with a chemical compounds.
The synthesis scheme described in prior art for L651582 orotate is shown in Reaction Scheme I above. 858 is a product identifier, e.g., 858A to 858D represent intermediates. 858E represents carboxyamidotriazole (CAI). 858F represents carboxyamidotriazole: orotic acid or carboxyamidotriazole:orotate, or CTO as defined herein.
Prior art teachings suggested use of choline orotate in combination with the drug to be a preferred embodiment. Unfortunately, this did not address the problems encountered in the present invention of scaling up the production of CTO for clinical development. It was not clear if the base:acid ratio in L651582 orotate (2:1) was the optimum chemical structure for the drug. Moreover, problems were encountered when scaling up the production of L651582 orotate (2:1) to manufacture large quantities. Few manufacturers had the equipment and facilities required to handle bulk quantities of sodium azide, and those contractors that had the facilities charged large service fees.
After protection of the alcohol group in 3,5-dichlorobenzyl alcohol, as the TBDMS ether step (step 1), the ether is reacted with 4 chlorobenzoyl chloride to form the substituted benzophene (step 2). The benzophene is treated with thionyl chloride (step 3) and then with sodium azide (step 4) to form 3,5-dichloro-4-(4-chlorobenzoyl)benzyl azide. Reaction of this azide with cyanoacetamide produces L651582 (step 5). Reaction of L651582 with orotic acid forms the L651582 orotate (2:1) (step 6).
The use of sodium azide in the above process in step 4 was a serious drawback to scaling up the production of L6515182 orotate in large quantities. Handling of large quantities of sodium azide has to be done in special pressure sensitive reactors since sodium azide is a high energy content hazardous material. The special containment facilities required to handle sodium azide generally increased the cost of manufacture because few drug manufacturers had the capacity to scale up the process to bulk amounts of the drug. This is because sodium azide is a rapidly acting, potentially deadly chemical that exists as an odorless white solid. When mixed with water or an acid, sodium azide changes rapidly to a toxic gas with a pungent odor. It also changes into toxic gas when it comes in contact with solid metals. Survivors of serious sodium azide poisoning may have heart and brain damage and Center for Disease Control and Prevention advises victims to its Hotline immediately. (CDC—Facts About Sodium Azide, 2009). Clearly, there was need to develop a safer, new, affordable and efficient process for the preparation of L651582 orotate without using sodium azide. Competitive bidding at affordable cost was impossible because sodium azide (Step 4) was required in the preparation of 3,5-dichloro-4-(4-chlorobenzoyl)benzyl azide, an intermediate, in the synthetic pathway for L651582 orotate, as shown above. It was therefore necessary to develop an alternate, safer more efficient process to prepare the orotate drug with the optimum chemical configuration and base:acid ratio. The present invention seeks to overcome these drawbacks.
Even though L651582 orotate was demonstrated to have significantly higher antitumor activity in the prostatic cancer rat model (U.S. Pat. No. 5,912,346) there was no teaching or suggestion regarding whether the chemical, pharmacological and biological properties of L651582 orotate in the base:acid ratio of 2:1 were optimum or not. Clearly, there is need to develop new polymorphs of CAI and an orotate compound of CAI that offers optimum chemical, biological, pharmacological, therapeutic and toxicokinetic characteristics to justify clinical development.
Thus, the primary objective of the invention was to develop an orotate formulation of CAI (wherein the base:acid ratio is in the range of 1:1 to 1:4) having improved effectiveness which is related to its bioavailability, which in turn is dependent on its solubility in human body fluids.
Another objective of the invention was to develop a safer, more cost effective process to produce bulk quantities of CAI, CTO (as orotate of CAI) and CAO (as formulation of CAI mixed with orotic acid).
An important objective of the invention was to make a safer CAI by using safer and less toxic ingredients to produce intermediates instead of using sodium azide or potassium azide which are highly toxic at very low concentrations. CAI produced by the processes described in prior art had been found to cause serious neurotoxicity and gastric toxicities in patients. Therefore, it was important to use of safer ingredients and an improved process to produce has also resulted in production of new polymorphs of CAI and its orotate formulations.
The pertinent subject matter of the above references is specifically incorporated herein by reference, in their entirety.